@article{MAKHILLJEAS2018131716765, title = {Microstructure and Mechanical Properties of DC-LSND Double Cooling on A-36 Steel Welded Joints}, journal = {Journal of Engineering and Applied Sciences}, volume = {13}, number = {17}, pages = {7341-7347}, year = {2018}, issn = {1816-949x}, doi = {jeasci.2018.7341.7347}, url = {https://makhillpublications.co/view-article.php?issn=1816-949x&doi=jeasci.2018.7341.7347}, author = {H.,M.N. and}, keywords = {DC-LSND double cooling,welded joints,distortion,liquid nitrogen,microstructure,refined}, abstract = {The use of certain welding techniques to reduce distortion in the welding of thin plates to the hull of a ship has become one of the most recent objects of research. One of the alternative welding techniques developed is called the DC-LSND (Dynamically Controlled Low Stress No-Distortion) technique. The investigation concerned here was aimed at studying the effect of DC-LSND double cooling on the distortion, microstructure and mechanical properties in A36 steel welded joints. The DC-LSND double cooling treatments were performed by cooling the HAZ (Heat Affected Zone) behind the welding torch by using cryogenic liquid nitrogen. A sequence of tests was carried out involving distortion measurement, microstructure examination, hardness measurement and tensile testing in combination with SEM fractography. The results showed that DC-LSND double cooling treatments affected transverse distortion significantly. The strength of the welded joint was improved by the DC-LSND double cooling treatments, based on the results of the tensile testing and the hardness. The microstructure was also refined by increasing the acicular ferrite phase.} }